A variety of techniques exist to map the geometry of an environment and objects within the environment and/or to determine the location of objects of interest within the environment. These methods can include applying one or more patterns of illumination to the environment (e.g., an array of vertical and/or horizontal lines of illumination) and imaging the environment, using one or more cameras, when exposed to such illumination. Additionally or alternatively, a particular object within the environment could include a tag configured to detect the emitted illumination. The location of the tag could be determined based on the detected illumination. In a further example, a particular object within the environment could include a tag configured to emit illumination and/or to reflect illumination. The location of the tag could be determined by imaging the environment with one or more cameras.